July 21 (Bloomberg) -- Diplomatic efforts to end two weeks
of Gaza Strip violence intensified after dozens of Palestinians
and 13 Israeli soldiers died in the conflict’s bloodiest single
day.

The Palestinian toll mounted to 514 today as fire from
fighter jets and tanks claimed dozens of lives across Gaza,
including nine children and adults killed in an airstrike on a
house, Gaza Health Ministry official Ashraf al-Qedra told
reporters. Twenty Israelis, including two civilians, have also
died since Israel escalated its campaign against Gaza militants
following weeks of rocket fire at its communities.

Israeli Prime Minister Benjamin Netanyahu said the
offensive in Hamas-controlled Gaza “will continue until it
achieves its aim: restoring quiet to the citizens of Israel for
an extended time,” according to an e-mail from his office.
Defense Minister Moshe Ya’alon said more troops entered Gaza
overnight and additional reserve soldiers may be called up,
according to an e-mailed statement.

The bloodshed in Gaza is further destabilizing a region
already mired in conflict from Iraq to Yemen. With death tolls
mounting and Israel’s ground operations escalating, the need to
find a formula to stanch the Gaza bloodshed grew more urgent.

Egypt’s Role

U.S. Secretary of State John Kerry is scheduled to arrive
in Egypt today to prod truce efforts. United Nations Secretary-General Ban Ki-moon is already in the Mideast, conferring with
regional leaders. Egypt, historically a mediator of Gaza-Israel
truces, proposed a plan last week that Israel accepted and Hamas
rejected.

Hamas said the proposal didn’t guarantee lifting Israel’s
blockade on Gaza, imposed in 2007 after the group wrested
control of the territory. Spokesman Fawzi Barhoum said yesterday
that “when we rejected the Egyptian initiative we didn’t reject
the Egyptian role.”

Sami Abu Zuhri, a Hamas spokesman in Gaza, said in an e-mailed statement that the diplomatic efforts to end the fighting
were meant to rescue Israel. “The armed resistance won’t
respond to the pressures and will dictate its conditions through
our superiority in the field,” Abu Zuhri said.

‘Serious Concern’

The number of Gazans seeking shelter from the fighting with
the UN Relief and Works Agency may soon be as high as about
100,000, the agency said in an e-mailed statement. Dubai began
airlifting emergency supplies to the territory on Sunday,
including 45,000 mattresses and 10,000 blankets, according to
the statement.

President Barack Obama, in a call with Netanyahu, “raised
serious concern” about growing civilian and military casualties
in Gaza, the White House said yesterday in an account of the
conversastion provided to reporters.

Eighty-seven Palestinians were killed yesterday, including
60 who died in Israeli artillery and tank fire in the Shuja’iya
neighborhood of Gaza City, according to Health Ministry
officials.

‘Doomsday’

“It was like doomsday,” Hanadi al-Kabariti, 33, said by
phone after she fled Shuja’iya. “There is nowhere to hide in
Gaza. It’s dangerous wherever you go.”

The Israeli military lost 13 soldiers yesterday, more than
it did in its entire three-week war in Gaza in 2009. Two of them
were U.S. citizens, the State Department said.

Kerry will seek a return to a 2012 truce Egypt brokered,
Obama told Netanyahu in their phone call, according to the White
House. That accord held out the possibility of easing Israeli
restrictions on the movement of people and goods in and out of
Gaza.

Hamas has demanded an end to all restrictions in any future
truce. The leader of Lebanon-based militant group Hezbollah,
Hassan Nasrallah, weighed in on the conflict today for the first
time, supporting Hamas’s “rightful demands to end the current
battle,” according to an e-mailed account of his conversation
with Hamas chief Khaled Mashaal.

Demilitarization Call

Israel has called for the demilitarization of Gaza and has
claimed good progress in diminishing the militants’ rocket
capabilities and crippling a network of tunnels they built to
carry out cross-border raids.

Destroying those passages is Israel’s stated objective of
the ground war it opened on July 17 after days of air strikes.
Two militant squads infiltrated Israel today through two
tunnels; one was hit by air and ground troops killed 10 gunmen
from the second group, the army said.

“I hope people don’t turn on the government,” said Joshua
Baskin, 37, a U.S. army veteran living in Israel. “I don’t
want people to change their minds on the ground invasion because
the army has to do its job to keep citizens safe.”

The “lion’s share” of the tunnels will be destroyed
within two to three days, Ya’alon said yesterday at a news
conference with Netanyahu in Tel Aviv. It was the first time
such a timetable has been given.

Today, Ya’alon said additional troops were sent in
overnight to locate additional passages. “We are prepared to
continue our activities as long as necessary, and if needed, we
will call up more reserve soldiers until we make Gaza quiet,”
Ya’alon told parliament’s Defense and Foreign Affairs Committee,
according to an e-mailed statement from the panel.